1. Field of the Invention
The present invention relates to a method for the flameproofing treatment for imparting a washing-resistant flame retardancy to cellulosic fibers or fibrous articles.
2. Description of the Related Art
As the flame retardant for cellulosic fibrous materials, there are known inorganic compounds such as ammonium phosphate, ammonium sulfamate, ammonium bromide, ammonium sulfate, borax, boric acid, guanidine phosphate and guanidine carbonate, organic halogen compounds such as chlorinated paraffin, decabromodiphenyl oxide, tetrabromobisphenol A and tris-2,3-dibromopropyl isocyanurate, phosphorus compounds such as trisdichloropropyl phosphate, trischloroethyl phosphate, tricresyl phosphate, trisisopropylphenyl phosphate, bis-2-chloroethylvinyl phosphonate and diphenyl hydrogenphosphite, and reactive phosphorus compounds such as tetrakishydroxymethyl phosphonium chloride (THPC), tetrakishydroxymethyl phosphonium sulfate (THPS) and dialkylphosphonopropionamide-methylol compounds.
When these flame retardants are applied to surfaces of cellulosic fibrous materials, the surfaces become white or sticky or the materials become rigid and coarse, with the result that the hand is drastically degraded. When water-soluble inorganic compounds are used, the hand is degraded by absorption of moisture. Furthermore, when reactive flame retardants such as THPC, THPS and N-hydroxymethyldialkylphosphonopropionamide are used according to prescribed methods, the strength of cellulosic fibrous materials is reduced by 20 to 60% and discoloration is caused in dyes, and moreover, bad odors are generated at the treating step and corrosive substances such as hydrogen chloride, sulfuric acid and formaldehyde are formed causing corrosion of treating equipment. Accordingly, devices for coping with bad odors and corrosive substances must be provided. Furthermore, this method is defective in that treated articles reek of bad odors.